The purpose of this study is to trace and explain the widespread deterioration of urban working class community life, by reference to the de-industrialization of cities. The study hypothesizes that de-industrialization, manifested primarily in the decline of manufacturing and related industries, erodes the networks of social and psychological support ordinarily developed in working class communities, as adaptations to the class circumstances in which people find themselves. These networks are both structural and cultural, encompassing organizations, institutions, traditions and values, and they define how a group perceives and reacts to its life chances. They are rooted in both community and workplace, and thus are highly sensitive to shifts in economic and occupational structure. The study's major theme is that de-industrialization strips the working class of its networks of support, thus undermining the social foundation for traditional urban working class communities. Such communities then give way to underclass or "lumpenproletarian" formations, characterized by a shifting and fluid associated life, and a mental outlook often marked by self-degradation. To test its hypothese, the study intensively investigates one working class district in New York: Brownsville, Brooklyn.